The two men appeared in a discussion, during which Mr Klitschko showed Mr Kozhara images of injuries he said were inflicted by the police on protesters.

Mr Kozhara suggested some of the opposition were right-wing extremists.

Ukraine has been in turmoil since November, when it scrapped an EU accord in favour of a Russian bailout.

"The Ukrainian people have shown and have proven that they are able to defend their decision on Europe despite repressive measures being taken," Mr Klitschko said, the Associated Press news agency reports.

He added that the opposition felt stronger because of the support from western friends of Ukraine.

'Extremist groups'

Earlier, European Council President Herman Van Rompuy had said the "future of Ukraine belongs with the EU" while US Secretary of State John Kerry had said the US backed Ukraine's "fight for democracy".

Neutrality is missing in Munich as rival sides ratchet up the rhetoric